<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Clac</title>
    <style>
      *{
        margin: 0;
        padding: 0;
        
      }
      .div {
        width: 100px;
        height: 100%;
      }
      .container{
        width: 100%;
        height: 100vh;
      }
      .div1 {
        float: left;
        background-color: lightblue;
      }
      .div2 {
        float: left;
        width: calc(100% - 200px);

        background-color: lightyellow;
      }
      .div3 {
        float: left;
        background-color: lightsalmon;
      }
    </style>
  </head>
  <body>
    <div class="container">
      <div class="div1 div"></div>
      <div class="div2 div">123</div>
      <div class="div3 div"></div>
    </div>
  </body>
</html>
